[Lldb-commits] [lldb] [lldb-dap] Refactoring IOStream into Transport handler. (PR #130026)

[Pavel Labath via lldb-commits]

================
@@ -0,0 +1,144 @@
+//===-- Transport.cpp -----------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "Transport.h"
+#include "DAPLog.h"
+#include "Protocol.h"
+#include "lldb/Utility/IOObject.h"
+#include "lldb/Utility/Status.h"
+#include "lldb/lldb-forward.h"
+#include "llvm/ADT/StringExtras.h"
+#include "llvm/ADT/StringRef.h"
+#include "llvm/Support/Error.h"
+#include "llvm/Support/raw_ostream.h"
+#include <string>
+#include <utility>
+
+using namespace llvm;
+using namespace lldb;
+using namespace lldb_private;
+using namespace lldb_dap;
+using namespace lldb_dap::protocol;
+
+static Expected<std::string> ReadFull(IOObject *descriptor, size_t length) {
+  std::string data;
+  data.resize(length);
+  auto status = descriptor->Read(data.data(), length);
+  if (status.Fail())
+    return status.takeError();
+  return data.substr(0, length);
+}
+
+static Expected<std::string> ReadUntil(IOObject *descriptor,
+                                       StringRef delimiter) {
+  std::string buffer;
+  buffer.reserve(delimiter.size() + 1);
+  while (!llvm::StringRef(buffer).ends_with(delimiter)) {
+    Expected<std::string> next =
+        ReadFull(descriptor, buffer.empty() ? delimiter.size() : 1);
+    if (auto Err = next.takeError())
+      return std::move(Err);
+    // '' is returned on EOF.
+    if (next->empty())
+      return buffer;
+    buffer += *next;
+  }
+  return buffer.substr(0, buffer.size() - delimiter.size());
+}
+
+/// DAP message format
+/// ```
+/// Content-Length: (?<length>\d+)\r\n\r\n(?<content>.{\k<length>})
+/// ```
+static const StringLiteral kHeaderContentLength = "Content-Length: ";
+static const StringLiteral kHeaderSeparator = "\r\n\r\n";
----------------
labath wrote:

The class documentation says it should be declared like this.

```suggestion
static constexpr StringLiteral kHeaderContentLength = "Content-Length: ";
static constexpr StringLiteral kHeaderSeparator = "\r\n\r\n";
```

https://github.com/llvm/llvm-project/pull/130026